Structural Breaks in the Game : The Case of Major League Baseball

To search for eras in a sports league, we utilize time series tests with structural breaks to identify eras in Major League Baseball performance. Using data from 1871-2010, the mean and standard deviation of four different performance measures are examined to test if deterministic or stochastic trends and structural breaks are present. Throughout, we identify breaks endogenously from the data. Perhaps most notable among our findings, we identify a deterministic trend in the mean slugging percentage in 1921 and 1992, which coincides with the early years of the free swinging (Babe Ruth) era and the modern steroid era, respectively